Journal of Oral & Facial Pain and Headache, 02/2015

Aims: To conduct a systematic review and meta-analysis to evaluate the effectiveness of hypnosis/relaxation therapy compared to no/minimal treatment in patients with temporomandibular disorders (TMD). Methods: Studies reviewed included randomized controlled trials (RCTs) where investigators randomized patients with TMD or an equivalent condition to an intervention arm receiving hypnosis, relaxation training, or hyporelaxation therapy, and a control group receiving no/minimal treatment. The systematic search was conducted without language restrictions, in Medline, EMBASE, CENTRAL, and PsycINFO, from inception to June 30, 2014. Studies were pooled using weighted mean differences and pooled risk ratios (RRs) for continuous outcomes and dichotomous outcomes, respectively, and their associated 95% confidence intervals (CI). Results: Of 3,098 identified citations, 3 studies including 159 patients proved eligible, although none of these described their method of randomization. The results suggested limited or no benefit of hypnosis/relaxation therapy on pain (risk difference in important pain -0.06; 95% CI: -0.18 to 0.05; P = .28), or on pressure pain thresholds on the skin surface over the temporomandibular joint (TMJ) and masticatory muscles. Low-quality evidence suggested some benefit of hypnosis/relaxation therapy on maximal pain (mean difference on 100-mm scale = -28.33; 95% CI: -44.67 to -11.99; P =.007) and active maximal mouth opening (mean difference on 100-mm scale = -2.63 mm; 95% CI: -3.30 mm to -1.96 mm; P .001) compared to no/minimal treatment. Conclusion: Three RCTs were eligible for the systematic review, but they were with high risk of bias and provided low-quality evidence, suggesting that hypnosis/relaxation therapy may have a beneficial effect on maximal pain and active maximal mouth opening but not on pain and pressure pain threshold. Larger RCTs with low risk of bias are required to confirm or refute these findings and to inform other important patient outcomes. Keywords: hypnotics and sedatives, pain, temporomandibular disorders (TMD), temporomandibular dysfunction syndrome, temporomandibular joint disorder

Aims: To use the Research Diagnostic Criteria for Temporomandibular Disorders (RDC/TMD) Axis II and additional pain-related and psychosocial variables to identify subtypes of TMD patients in a primary health care setting based on pain-related disability. Methods: Consecutive TMD pain patients (n = 399) seeking treatment in a primary care setting completed a multidimensional pain questionnaire. Subtyping was based on the Graded Chronic Pain Scale (GCPS), and the patients were divided into a no-disability group (0 disability points), lowdisability group (1-2 disability points), and high-disability group (3-6 disability points). Psychosocial variables included RDC/TMD Axis II variables, anxiety, tension and stress, worry, catastrophizing, coping ability, general health, and other pain problems. Subtype differences were analyzed with t test, Wilcoxon rank-sum test, ANOVA, or Kruskal-Wallis test. A further analysis with multivariable logistic model was applied. All P values from pairwise comparisons were Bonferroni adjusted. Results: Most (61%) of the patients belonged to the no-disability group, 27% to the low-disability group, and 12% to the high-disability group. When subtypes were compared, patients in the no-disability group appeared psychosocially well-functioning, with fewer symptoms related to psychosocial distress, better ability to control pain, and fewer jaw functional limitations and other pain problems. Patients in the high-disability group reported the highest levels of symptoms of depression and somatization, sleep dysfunction, worry, and catastrophizing thoughts. The low-disability patients formed an intermediate group between the no-disability and high-disability groups. Conclusion: The results suggest that GCPS-related disability scoring can be used as a simple screening instrument in primary care settings to identify individuals with different, clinically relevant psychosocial subtypes. Keywords: biopsychosocial, Graded Chronic Pain Scale, primary health care, RDC/TMD Axis II, TMD pain

Aims: To examine the extent of depression, anxiety, somatization, and comorbidity between depression and anxiety in patients with temporomandibular disorders (TMD) by adding the Symptom Checklist-90 Revised self-report questionnaire for anxiety to the Research Diagnostic Criteria for TMD. Methods: A total of 207 Israeli TMD patients were included in this retrospective study. Data included levels of depression, anxiety, somatization, and comorbidity in the study group as a whole, in chronic pain TMD patients compared to acute pain TMD patients, and in chronic pain TMD patients according to their Graded Chronic Pain Scale score. Spearman correlation was used to assess the level of correlation between depression, anxiety, and somatization. Fisher exact test or Pearson chi-square test was used to compare the categorical variables. Results: When depression, anxiety, somatization, and comorbidity were analyzed in a multidimensional approach, there were statistically significant differences between subgroups as to depression and somatization only. No statistically significant differences were found as to anxiety and comorbidity. Conclusion: Multidimensional assessment enabled differentiation between findings of depression, anxiety, somatization, and comorbidity in subgroups of TMD patients. The findings of no statistically significant differences between subgroups of TMD patients as to anxiety and comorbidity support previous studies on TMD and anxiety, which suggest a less significant role of anxiety in chronic TMD patients as compared to depression and somatization. Keywords: anxiety, comorbidity, depression, RDC/TMD

Aims: To evaluate, in an open trial, the pharmacotherapeutic efficacy of tricyclic antidepressant (TCA) drugs and gabapentin in patients with persistent myofascial pain and to identify patient and pain characteristics that may predict treatment outcome. Methods: A stepped pharmacotherapeutic protocol was employed. All 42 patients having persistent facial pain with tenderness of regional muscles were first prescribed amitriptyline, but those with side effects were subsequently transferred to nortriptyline. In patients where no response to TCAs was observed, gabapentin was initiated. Outcome was assessed by employing prospective diaries recording pain intensity measured with an 11-point (0-10) verbal pain scale (VPS). Individual characteristics in these patients and their influence on drug response and outcome were analyzed; specifically, patients treated with TCAs were compared with those subsequently treated with gabapentin. Chisquare and t tests were used to analyze the data. Results: A total of 23 patients responded to TCAs and continued on this regimen, while 19 were resistant to TCAs and were subsequently treated with gabapentin. Their mean (± SD) VPS score at baseline was 6.5 ± 1.9 on an 11-point scale. In TCA-treated patients, 43% showed ≥ 50% reduction in pain intensity. This was achieved with a mean amitriptyline dose of 16 ± 1.1 mg/d and a mean nortriptyline dose of 25 ± 2.1 mg/d. Patients who did not respond to TCAs were characterized by a significantly higher age, more comorbid medical illness, and evidence of more regional pain spread (P .05). In spite of not responding to TCAs, 36.8% of this group showed ≥ 50% reduction in pain intensity following gabapentin therapy at a mean daily dose of 973.7 ± 68.8 mg. Overall, a stepped approach employing TCAs and gabapentin resulted in 54.8% of all treated patients reporting improvements of ≥ 50% in VPS scores. Conclusion: This study has demonstrated the good pharmacotherapeutic response of persistent myofascial pain, even in more severe cases. Not being a randomized controlled trial, the results may be biased and should be interpreted with caution. Patients who do not respond to TCAs may be a distinct subgroup and this needs further investigation. The results also suggest that gabapentin, at a lower dose than previously reported, is a good alternative in TCA-resistant patients. Keywords: amitriptyline, antiepileptic drug, myalgia, nortriptyline, orofacial pain

Aims: To explore the point prevalence of painful temporomandibular disorders (TMD) in a well-characterized clinical cohort of postural orthostatic tachycardia syndrome (PoTS) sufferers and to understand the functional and physiologic impact of this comorbidity on the patient. Methods: Patients with PoTS were retrospectively recruited from a previous study conducted in a UK hospital setting. Data had previously been collected on several parameters, including sociodemographic, physiologic, and functional. The participants were mailed a highly sensitive (99%) and specific (97%) self-report screening instrument for painful TMD. Simple descriptive statistics with Fisher Exact and Kruskal-Wallis tests were used to examine the data and draw inferences from it. Results: A total of 36 individuals responded (69% response rate). Just under half (47%) of the sample screened positive for painful TMD. There was no significant difference between the screening result for TMD or previously reported headaches or joint pain (P > .05). Chronic fatigue syndrome (CFS) was diagnosed by the Fukuda Criteria in 44% of the total sample and in 56% of those with painful TMD. There were no significant differences in physiologic parameters in CFS and TMD. TMD caused a significant decrease in quality of life as measured by the Patient-Reported Outcomes Measurement Information System, Health Assessment Questionnaire (P .05). Conclusion: TMD are common in patients with PoTS. They have a significant, additional impact on patients' quality of life and should therefore be screened for at an early stage in PoTS. Keywords: postural orthostatic tachycardia syndrome, quality of life, temporomandibular disorders

Aims: To determine whether glutamate-evoked jaw muscle pain is altered by the temperature of the solution injected. Methods: Sixteen healthy volunteers participated and received injections of hot (48°C), neutral (36°C), or cold (3°C) solutions (0.5 mL) of glutamate or isotonic saline into the masseter muscle. Pain intensity was assessed with an electronic visual analog scale (eVAS). Numeric rating scale (NRS) scores of unpleasantness and temperature perception, pain-drawing areas, and pressure pain thresholds (PPTs) were also measured. Participants filled out the McGill Pain Questionnaire (MPQ). Two-way or three-way repeated measures ANOVA were used for data analyses. Results: Injection of hot glutamate and cold glutamate solutions significantly increased and decreased, respectively, the peak pain intensity compared with injection of neutral glutamate solution. The duration of glutamate-evoked pain was significantly longer when hot glutamate was injected than when cold glutamate was injected. No significant effect of temperature on pain intensity was observed when isotonic saline was injected. No effect of solution temperature was detected on unpleasantness, heat perception, cold perception, area of pain drawings, or PPTs. There was a significantly greater use of the "numb" term in the MPQ to describe the injection of cold solutions compared to the injection of both neutral and hot solutions. Conclusion: Glutamate-evoked jaw muscle pain was significantly altered by the temperature of the injection solution. Although temperature perception in the jaw muscle is poor, pain intensity is increased when the muscle tissue temperature is elevated. Keywords: glutamate-evoked pain, musculoskeletal pain, pain assessment, temperature measurement

Aims: To assess reports of dental pain in a school-based sample of children in South Brazil and test its association with socioeconomic, demographic, psychosocial, and clinical variables. Also, the consequences of dental pain on oral health perception and its impact on daily life were investigated. Methods: A two-stage cluster procedure was used to select 1,199 children in 20 public and private schools in Pelotas, Brazil. Children were interviewed to obtain selfreports of dental pain. They were also asked about perception of their oral health and dental fear. Mothers answered a questionnaire on socioeconomic characteristics. A clinical oral examination was conducted to assess dental caries, malocclusion, and dental trauma. Multivariate Poisson regression analysis was used to investigate factors associated with dental pain in the previous 6 months and its effect on oral health perception. Results: The prevalence of dental pain was 35.7% (95% confidence interval [CI] 33.0-38.5) in the previous 6 months. A higher prevalence of dental pain was observed for children from lower-income families (prevalence ratio [PR] 1.39; 95% CI 1.10-1.76), for girls (PR 1.24; 95% CI 1.06-1.46), for those living in overcrowded houses (PR 1.23; 95% CI 1.01-1.49), for those who reported dental fear (PR 1.19; 95% CI 1.00-1.42), and for those with caries experience (PR 1.57; 95% CI 1.34- 1.84), after adjustments. Dental pain presence influenced oral health perception (PR 2.56; 95% CI 1.55-3.29) and impacted the children's daily life (PR 1.89; 95% CI 1.64-2.17). Conclusion: A high percentage of schoolchildren suffered from dental pain, which was influenced by demographic, socioeconomic, psychosocial, and clinical characteristics, causing a negative impact on oral health perception. Keywords: children, dental caries, dental pain, epidemiology, socioeconomic

Aims: To evaluate and compare the validity of the PainDETECT, DN4, and abbreviated DN4 (DN4i) neuropathic pain questionnaires for primary burning mouth syndrome (BMS), which is a burning sensation in the oral mucosa in the absence of any identifiable organic etiology. Methods: Eighty-one patients (42 with primary BMS and 39 with nociceptive pain) complaining of a burning sensation and pain in their oral mucosa were enrolled in this study. All of the patients completed the neuropathic pain questionnaires. The sensitivity, specificity, positive predictive value, negative predictive value, and the area under the receiver operating characteristic (ROC) curve were estimated. Then the relationship between pain intensity and total neuropathic pain score was investigated. Data were analyzed with the chi-square test and independent t test for subjects' baseline characteristic differences, and with Pearson correlation coefficients for the relationship of variables. Results: The mean area under the ROC curves (AUCs) for PainDETECT, DN4, and DN4i were 0.81, 0.79, and 0.81, respectively. There was no statistically significant difference in the AUCs among the questionnaires. PainDETECT, DN4, and DN4i had a lower sensitivity and specificity for BMS compared to previous validation studies. The total scores for PainDETECT, DN4, and DN4i in the primary BMS group were significantly associated with pain intensity. Conclusion: Although the results of this study suggest that neuropathic pain questionnaires, such as PainDETECT and DN4, are not ideal principal screening tools for BMS patients, a substantial proportion of neuropathic symptoms in primary BMS patients were identified. Keywords: burning mouth syndrome, DN4, neuropathic pain questionnaire, PainDETECT

Aims: To determine whether self-regulation can be studied successfully in a rodent model and whether persistent facial pain influences self-regulatory behavior. Methods: Thirty male Sprague-Dawley rats, divided into two groups, (1) chronic constriction injury of the infraorbital nerve (CCI-ION) and (2) naïve, were used in a two-part behavioral paradigm of self-regulation. This paradigm consisted of both a cued go/no-go task (part one) and a persistence trial (part two). All animals were acclimated and trained for a period of 4 weeks prior to the experimental manipulation and then tested for a total of 5 weeks following experimental manipulation. Results were analyzed with t tests, one-way analysis of variance, and two-way, repeated measures analysis of variance. Results: CCI-ION surgery induced significant mechanical hypersensitivity of the ipsilateral whisker pad that began 3 weeks postsurgery and persisted through the duration of the experiment (P .001). At weeks 4 and 5 post-experimental manipulation, naïve animals demonstrated a significant decrease in lever presses during the persistence task (P .05) compared to baseline, whereas CCI-ION animals did not (P = .55). Conclusion: These results suggest that persistent pain influences behavioral regulation and that animals experiencing persistent pain may have difficulty adapting to environmental demands. Keywords: chronic constrictive injury, infraorbital nerve, learning, orofacial pain, self-regulation

Aims: To determine whether behavioral, anatomical, and physiologic endpoints widely used to infer the presence of pain in rodent models of temporomandibular disorders (TMD) were applicable to the rabbit model of TMD associated with altered joint loading. Methods: Unilateral molar dental splints were used to alter temporomandibular joint (TMJ) loading. Changes in nociceptive threshold were assessed with a mechanical probing of the TMJ region on nine splinted and three control rabbits. Fos-like immunoreacitivty in the trigeminal subnucleus caudalis was assessed with standard immunohistochemical techniques from three splinted and six control animals. Retrogradely labeled TMJ afferents were studied with patch-clamp electrophysiologic techniques from three splinted and three control animals. Remodeling of TMJ condyles was assessed by histologic investigations of three splinted and three control animals. A Student t test or a Mann-Whitney U test was used with significance set at P .05 to compare splinted to control samples. Results: While variable, there was an increase in mechanical sensitivity in splinted rabbits relative to controls. The increase in Fos+ cells in splinted rabbits was also significant relative to naïve controls (86 ± 8 vs 64 ± 15 cells/section, P .05). The rheobase (364 ± 80 pA) and action potential threshold (-31.2 ± 2.0 mV) were higher in TMJ afferents from splinted rabbits compared to controls (99 ± 22 pA and -38.0 ± 2.0 mV, P .05). There was significant remodeling in the condylar fibrocartilage layers as manifested by a change in glycosaminoglycan distribution and a loss of defined cell layers. Conclusion: Behavioral and anatomical results were consistent with an increase in nociceptive signaling in concert with condylar remodeling driven by altered TMJ loading. Changes in excitability and action potential waveform were consistent with possible compensatory changes of TMJ afferents for an overall increase in afferent drive associated with joint degeneration. These compensatory changes may reflect pain-adaption processes that many patients with TMJ disorders experience. Keywords: altered loading, fibrocartilage degeneration, pain assessments, temporomandibular joint, unilateral splint

The case of a 32-year-old woman who sustained a nasal bone fracture and dental trauma at the age of 9 is described in this article. Misdiagnosis of the dental displacement into the middle turbinate at the initial examination led to chronic facial pain. The cause of the pain was incorrectly diagnosed or misinterpreted by several medical specialists, including an otolaryngologist, neurologist, physiatrist, ophthalmologist, internist, radiologist, oral surgeon, dentist, and the patient's family physician. Finally, 23 years after the dental trauma, a multislice computed tomogram revealed that the primary maxillary canine was dislocated into the right middle nasal concha. The tooth, which had become embedded into necrotic, inflammatory tissue, was removed by endoscopic surgery, which resulted in full resolution of the patient's pain. Keywords: chronic facial pain, middle turbinate, misdiagnosis, tooth displacement